Website operators may often seek to generate revenue by including content external to their website into their web pages or other network content. Such external content may comprise advertisements or other types of content. Unfortunately, since such external content is typically downloaded by a client browser when a given web page is rendered on a client, it is possible that malicious components can be inserted into the external content without knowledge of the website operators. In such a case, the website operators may be deemed to have distributed malicious components in their web pages even though such distribution was done by the party who generated the external content.